From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 900B3C38BFA for ; Mon, 24 Feb 2020 22:00:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B9972176D for ; Mon, 24 Feb 2020 22:00:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728185AbgBXWAg (ORCPT ); Mon, 24 Feb 2020 17:00:36 -0500 Received: from mga06.intel.com ([134.134.136.31]:22327 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727421AbgBXWAf (ORCPT ); Mon, 24 Feb 2020 17:00:35 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Feb 2020 14:00:33 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,481,1574150400"; d="scan'208";a="284477336" Received: from otc-lr-04.jf.intel.com ([10.54.39.48]) by FMSMGA003.fm.intel.com with ESMTP; 24 Feb 2020 14:00:33 -0800 From: kan.liang@linux.intel.com To: acme@kernel.org, jolsa@redhat.com, mingo@redhat.com, peterz@infradead.org, linux-kernel@vger.kernel.org Cc: mark.rutland@arm.com, namhyung@kernel.org, ravi.bangoria@linux.ibm.com, yao.jin@linux.intel.com, ak@linux.intel.com, Kan Liang Subject: [PATCH V2 0/5] Support metric group constraint Date: Mon, 24 Feb 2020 13:59:19 -0800 Message-Id: <1582581564-184429-1-git-send-email-kan.liang@linux.intel.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kan Liang Changes since V1: - Remove global static flag violate_nmi_constraint, and add a new function metricgroup___watchdog_constraint_hint() for all watchdog constraint hints in patch 4. The rest of the patches are not changed. Some metric groups, e.g. Page_Walks_Utilization, will never count when NMI watchdog is enabled. $echo 1 > /proc/sys/kernel/nmi_watchdog $perf stat -M Page_Walks_Utilization Performance counter stats for 'system wide': itlb_misses.walk_pending (0.00%) dtlb_load_misses.walk_pending (0.00%) dtlb_store_misses.walk_pending (0.00%) ept.walk_pending (0.00%) cycles (0.00%) 2.343460588 seconds time elapsed Some events weren't counted. Try disabling the NMI watchdog: echo 0 > /proc/sys/kernel/nmi_watchdog perf stat ... echo 1 > /proc/sys/kernel/nmi_watchdog The events in group usually have to be from the same PMU. Try reorganizing the group. A metric group is a weak group, which relies on group validation code in the kernel to determine whether to be opened as a group or a non-group. However, group validation code may return false-positives, especially when NMI watchdog is enabled. (The metric group is allowed as a group but will never be scheduled.) The attempt to fix the group validation code has been rejected. https://lore.kernel.org/lkml/20200117091341.GX2827@hirez.programming.kicks-ass.net/ Because we cannot accurately predict whether the group can be scheduled as a group, only by checking current status. This patch set provides another solution to mitigate the issue. Add "MetricConstraint" in event list, which provides a hint for perf tool, e.g. "MetricConstraint": "NO_NMI_WATCHDOG". Perf tool can change the metric group to non-group (standalone metrics) if NMI watchdog is enabled. After applying the patch, $echo 1 > /proc/sys/kernel/nmi_watchdog $perf stat -M Page_Walks_Utilization Splitting metric group Page_Walks_Utilization into standalone metrics. Try disabling the NMI watchdog to comply NO_NMI_WATCHDOG metric constraint: echo 0 > /proc/sys/kernel/nmi_watchdog perf stat ... echo 1 > /proc/sys/kernel/nmi_watchdog Performance counter stats for 'system wide': 18,253,454 itlb_misses.walk_pending # 0.0 Page_Walks_Utilization (50.55%) 78,051,525 dtlb_load_misses.walk_pending (50.55%) 29,213,063 dtlb_store_misses.walk_pending (50.55%) 0 ept.walk_pending (50.55%) 2,542,132,364 cycles (49.92%) 1.037095993 seconds time elapsed Kan Liang (5): perf jevents: Support metric constraint perf metricgroup: Factor out metricgroup__add_metric_weak_group() perf util: Factor out sysctl__nmi_watchdog_enabled() perf metricgroup: Support metric constraint perf vendor events: Add NO_NMI_WATCHDOG metric constraint .../arch/x86/cascadelakex/clx-metrics.json | 3 +- .../pmu-events/arch/x86/skylake/skl-metrics.json | 3 +- .../pmu-events/arch/x86/skylakex/skx-metrics.json | 3 +- tools/perf/pmu-events/jevents.c | 19 ++-- tools/perf/pmu-events/jevents.h | 2 +- tools/perf/pmu-events/pmu-events.h | 1 + tools/perf/util/metricgroup.c | 109 ++++++++++++++++----- tools/perf/util/stat-display.c | 6 +- tools/perf/util/util.c | 18 ++++ tools/perf/util/util.h | 2 + 10 files changed, 128 insertions(+), 38 deletions(-) -- 2.7.4